Demulsifying compositions and methods of use

ABSTRACT

Methods for resolving emulsions in a hydrocarbon stream by contacting the hydrocarbon stream with a demulsifying composition are disclosed. Demulsifying compositions for treating a hydrocarbon stream are also disclosed, wherein the demulsifying composition comprises at least one C4-C12 alkyl phenol-formaldehyde resin alkoxylate.

FIELD OF THE INVENTION

The present invention relates to compositions and processes for breakingemulsions in crude oil. More particularly, the compositions andprocesses may be used to break water-in-oil emulsions at an oilfield orin a desalter in a crude oil refinery.

BACKGROUND OF THE INVENTION

Crude oil is produced from geological formations where it is in intimatecontact with brine (salt water). As the oil and brine are produced,their movement through geological formations produces an emulsion ofwater-in-oil, wherein tiny droplets of water are suspended in acontinuous phase of oil. Generally, the amount of water produced fromthe formation in the oil field ranges from 1-2% and may even be higherthan 90%. Refineries operate with much lower water content in the crudeoil, generally not exceeding 0.5%.

In oilfield industries, these water-in-oil emulsions are often referredto as primary emulsions. Though less common, oil-in-water emulsions,wherein tiny droplets of oil are suspended in a continuous phase ofwater, also occur and are often referred to as reverse emulsions.Another type of emulsion is a multiple, or complex, emulsion where tinydroplets are suspended in bigger droplets that are suspended in acontinuous phase.

To render the crude oil more suitable for refining, the crude oil isdemulsified by separating the primary or reverse emulsions into separateoil and water phases. While the water in the oil is a problem forrefiners, it is the dissolved salts which cause the most problems sincethey can deposit and foul heat transfer surfaces. Calcium chloride andmagnesium chloride decompose at operating temperatures of the refineryto produce HCl (hydrochloric acid) which corrodes the distillationtowers. To remove the brine and the salts it contains, the crude oil isheated to around 120° C. and mixed with about 5% fresh water by passingthe water and oil through a mixing valve and thence to a vessel, such asan oil refinery desalter, where it has a residence time of about 30minutes to allow the emulsion to break and the oil and water toseparate.

Generally, the steps in demulsification are flocculation followed bycoalescence and, finally, sedimentation. During the flocculation step,the suspended droplets aggregate to form larger droplets. Duringcoalescence, the larger droplets come together to form a large drop.Sedimentation takes advantage of the fact that water is denser than oil.During sedimentation the water and oil phases become stratified intodistinct layers as large drops of water fall to the bottom. There areseveral methods for demulsifying oil field emulsions, including thermal,mechanical, electrical, and chemical methods.

Chemical methods employ the use of chemicals that neutralize the effectsof emulsion stabilizing agents and to accelerate the demulsificationprocess by reducing the interfacial tension. These demulsifyingchemicals are often referred to as emulsion “breakers” because theybreak, or separate the emulsions into the separate oil and water phases.Demulsifying chemicals used to break water-in-oil emulsions, or primaryemulsions, are often referred to as primary emulsion breakers. Primaryemulsion breakers are added to the continuous oil phase and aregenerally oil-soluble. Likewise, demulsifying chemicals used to breakoil-in-water emulsions, or reverse emulsions, are often referred to asreverse emulsion breakers. Reverse emulsion breakers are generallywater-soluble, though they may be oil-soluble, and are added to thecontinuous water phase. Some of the water is removed from the crude oilby adding surfactant chemicals to demulsify the water and oil at thewell or near the point of production. These surfactants are optimized toseparate, or “break”, the oil and water at relatively low temperatures,common in the oil field.

Without emulsion breakers, more time is required to separate the phases,limiting the amount of oil the refinery can process. In some cases, forexample when a multiple emulsion is present, crude oil applicationsrequire both primary and reverse emulsion breakers. As primary emulsionbreakers generally are oil soluble and reverse emulsion breakers aregenerally water soluble, the two types of emulsion breakers do not mixand are added to the crude oil or to the wash water separately.

The most effective demulsifying chemistries and formulations typicallyvary with the crude composition. The crude composition, however,continuously varies based on the crude source or well, the treatment, ifany, at the well, well stimulation practices, “smearing”, orcontamination effects from adjacent pipeline transports, and the crudeblend composition. The crude composition may be further altered by amyriad of chemistries that may have been added to the crude between thetime it is collected at the well and the time it enters a desalter at arefinery. Such chemistries may include, but are not limited to,corrosion inhibitors, biocides, drag reducers, H₂S scavengers, etc.

Most of the effects on crude composition mentioned above are beyond arefinery's control, yet the refinery is often left with the burden ofanalyzing the crude composition and determining the most effectivedemulsifying treatment.

BRIEF DESCRIPTION OF THE INVENTION

It was surprisingly discovered, however, that blends of one or moreC₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylates with a surfactantproduced a robust demulsifying composition that was effective atresolving emulsions in a variety of crude types.

Accordingly, in one embodiment, a method of resolving an emulsionpresent in a hydrocarbon stream is disclosed. The method may comprisecontacting the hydrocarbon stream with a demulsifying composition. Thedemulsifying composition may comprise at least one C₄-C₁₂ alkylphenol-formaldehyde resin alkoxylate, an oil phase, and an aqueousphase, wherein the oil and aqueous phases form a colloidal micellarsolution. In another embodiment, the C₄-C₁₂ alkyl phenol-formaldehyderesin alkoxylate may have a polymerization number of 2-20 and a degreeof alkoxylation greater than about 30% and less than about 90% relativeto the weight of the resin.

In yet another embodiment, the demulsifying composition may comprise 0.1wt % to about 90 wt % water based on a total weight of the demulsifyingcomposition. Alternatively, the demulsifying composition may comprise0.1 wt % to about 30 wt % water based on a total weight of saiddemulsifying composition.

In another embodiment, the C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate may comprise at least two alkyl phenol-formaldehyde resinalkoxylates having different amounts of alkoxylation. The two alkylphenol-formaldehyde resin alkoxylates may comprise a first alkylphenol-formaldehyde resin alkoxylate, having a percent A by weight ofalkoxylation, and a second alkyl phenol-formaldehyde resin alkoxylate,having a percent B by weight of alkoxylation, wherein A minus B is10-50%. The ratio by weight of the first alkyl phenol-formaldehyde resinalkoxylate relative to the second alkyl phenol-formaldehyde resinalkoxylate may be 1:9 to 9:1.

In yet another method embodiment, the demulsifying composition may beadded to the hydrocarbon stream in an amount ranging from about 1 toabout 200 ppm by volume of the hydrocarbon stream.

In another embodiment, the demusifying composition may further compriseat least one polyalkylene oxide polyol with a degree of ethoxylationgreater than about 30% and less than about 85% and a molecular weightranging from about 1000 to about 25,000. The ratio by weight of theC₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylate to the polyalkyleneoxide polyol may range from about 1:9 to about 9:1. In yet anotherembodiment, at least one polyalkylene oxide polyol may comprise twopolyalkylene oxide polyols, wherein at least one of the polyalkyleneoxide polyols may be selected from the group consisting of ethyleneoxide/propylene oxide block polymers, ethylenediamine alkoxylates,polyethylenimine alkoxylates, glycerol alkoxylates, trimethylpropanealkoxylates, and sorbitol alkoxylates.

In yet another embodiment, the first polyalkylene oxide polyol may be anethylene oxide/propylene oxide block copolymer having the formula:

wherein x, y, and z are any integer greater than one, and the moleculehas a molecular weight of 1000-9000. The second polyalkylene oxidepolyol may be an oxide block copolymer having a molecular weight of3000-25000 and 2-6 branches. Each branch may comprise at least onepolyalkoxylate block.

In another embodiment, the demulsifying composition may further comprisea water-soluble reverse emulsion breaker and/or a water-solublecorrosion inhibitor. The reverse emulsion breaker may comprise at leastone water-soluble polymer selected from the group consisting ofpolyamines and dialkyl diallyl ammonium polymers. In another embodiment,the reverse emulsion breaker may comprise aluminum chlorohydrate andpoly(diallyldimethylammonium chloride). The poly(diallyldimethylammoniumchloride) may have a molecular weight of about 100,000. The weight ratioof aluminum chlorohydrate to poly(diallyldimethylammonium chloride) maybe about 9:1.

In yet another embodiment, the corrosion inhibitor may comprise at leastone member selected from the group consisting of amidoethyl imidazoline,hydroxyethyl imidazoline, and aminoethyl imidazoline.

In another embodiment, the demulsifying composition may comprise atleast one member selected from the group consisting of an acid, anon-polar organic solvent, a base, a wetting agent, and a dispersant.Suitable acids include, but are not limited to, acetic acid, citricacid, malic acid, maleic acid, succinic acid, glycolic acid, methanesulfonic acid, dodecylbenzenesulfonic acid, naphthalene sulfonic acid,and p-toluene sulfonic acid. Suitable non-polar organic solventsincludes, but are not limited to, naphtha, light aromatic naphtha, heavyaromatic naphtha, pentane, cyclopentane, hexane, cyclohexane, benzene,ethyl benzene, 1,2,4-trimethyl benzene, 1,3,5-trimethyl benzene,toluene, xylene, cumene, 1,4-dioxane, chloroform, diethyl ether, methylesters of fatty acids (biodiesel), and diethylene glycol butyl ether.Suitable bases include, but are not limited to, sodium hydroxide andpotassium hydroxide. Suitable wetting agents include, but are notlimited to sodium dioctyl sulfosuccinic acid and sodium dodecylbenzenesulfonic acid. Suitable dispersants include adducts of at least onemono- or polycarboxylic acid or anhydride and an acylating reagent.Suitable acylating reagents include, but are not limited to, fumaricacid, maleic anhydride, maleic acid, succinic anhydride, and succinicacid.

In yet another embodiment, the C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate may comprise at least one member selected from the groupconsisting of: a) a mixed resin with units of nonylphenol formaldehydealkoxylate and units of butylphenol formaldehyde alkoxylate; b) a resinwith units of nonylphenol formaldehyde alkoxylate; and c) a resin withunits of amylphenol formaldehyde alkoxylate.

In another method embodiment, the hydrocarbon stream may comprise crudeoil.

In another embodiment, a demulsifying composition for treating ahydrocarbon stream is provided. The demulsifying composition maycomprise at least one C₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylate,an oil phase, and an aqueous phase, wherein the oil and aqueous phasesform a colloidal micellar solution. The demulsifying composition maycomprise 0.1 wt % to about 90 wt % water based on a total weight of saiddemulsifying composition.

In another embodiment, the C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate may have a polymerization number of 2-20 and a degree ofalkoxylation greater than about 30% and less than about 90% relative tothe weight of the resin. In yet another embodiment, the demulsifyingcomposition may comprise from about 0.1 wt % to about 30 wt % water,based on a total weight of said demulsifying composition.

In another embodiment, the C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate comprises at least two alkyl phenol-formaldehyde resinalkoxylates having different amounts of alkoxylation. The two alkylphenol-formaldehyde resin alkoxylates may comprise a first alkylphenol-formaldehyde resin alkoxylate, having a percent A by weight ofalkoxylation, and a second alkyl phenol-formaldehyde resin alkoxylate,having a percent B by weight of alkoxylation, wherein A minus B is10-50%. The ratio by weight of an amount of the first alkylphenol-formaldehyde resin alkoxylate relative to the second alkylphenol-formaldehyde resin alkoxylate may be 1:9 to 9:1.

In yet another embodiment, the demulsifying composition may furthercomprise at least one polyalkylene oxide polyol with a degree ofethoxylation greater than about 30% and less than about 85% and amolecular weight ranging from about 1000 to about 25,000. The ratio byweight of the C₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylate to thepolyalkylene oxide polyol may range from about 1:9 to about 9:1. Inanother embodiment, the polyalkylene oxide polyol may comprise twopolyalkylene oxide polyols, wherein one of the polyalkylene oxidepolyols may be selected from the group consisting of ethyleneoxide/propylene oxide block polymers, ethylenediamine alkoxylates,polyethylenimine alkoxylates, glycerol alkoxylates, trimethylpropanealkoxylates, and sorbitol alkoxylates.

In yet another embodiment, the first polyalkylene oxide polyol may be anethylene oxide/propylene oxide block copolymer having the formula:

wherein x, y, and z are any integer greater than one, and the moleculehas a molecular weight of 1000-9000. The second polyalkylene oxidepolyol may be an oxide block copolymer having a molecular weight of3000-25000 and 2-6 branches. Each branch may comprise at least onepolyalkoxylate block.

In another embodiment, the aqueous phase may further comprise awater-soluble reverse emulsion breaker and/or a water-soluble corrosioninhibitor. Reverse emulsion breakers are materials that aid inflocculation or coalescence of crude-oil in water emulsions. As such,reverse emulsion breakers may be categorized as flocculants orcoagulants. Coagulants are low molecular weight (<1 MM) polyamines,poly(diallyldimethylammonium chloride), acryloyloxyethyl trimethylammonium chloride/tannin polymers, quaternized starches, and melamineformaldehyde polymers. Flocculants are higher molecular weight (2-12 MM)polymers of acrylamide with poly(diallyldimethylammonium chloride) oracryloyloxyethyl trimethyl ammonium chloride. The reverse emulsionbreaker may be present at about 0.5 wt % to about 10 wt % based on atotal weight of the demulsifying composition. Alternatively, the reverseemulsion breaker may be present at about 0.5 wt % to about 5 wt % basedon a total weight of the demulsifying composition. In one embodiment,the reverse emulsion breaker may comprise at least one water-solublepolymer selected from the group consisting of polyamines and dialkyldiallyl ammonium polymers. In yet another embodiment, the reverseemulsion breaker may comprise aluminum chlorohydrate andpoly(diallyldimethylammonium chloride). The poly(diallyldimethylammoniumchloride) may have a molecular weight of about 100,000. The weight ratioof aluminum chlorohydrate to poly(diallyldimethylammonium chloride) maybe about 9:1. In yet another embodiment the corrosion inhibitor maycomprise at least one member selected from the group consisting ofamidoethyl imidazoline, hydroxyethyl imidazoline, and aminoethylimidazoline. The corrosion inhibitor may be present at about 0.5 wt % toabout 10 wt % based on a total weight of the demulsifying composition.Alternatively, the corrosion inhibitor may be present at about 0.5 wt %to about 5 wt % based on a total weight of the demulsifying composition.

In another embodiment, the demulsifying composition may further compriseat least one member selected from the group consisting of an acid, anon-polar organic solvent, a base, a wetting agent, and a dispersant.Suitable acids include, but are not limited to, acetic acid, citricacid, malic acid, maleic acid, succinic acid, glycolic acid, methanesulfonic acid, dodecylbenzenesulfonic acid, naphthalene sulfonic acid,and p-toluene sulfonic acid. Suitable non-polar organic solventsinclude, but are not limited to, naphtha, light aromatic naphtha, heavyaromatic naphtha, pentane, cyclopentane, hexane, cyclohexane, benzene,ethyl benzene, 1,2,4-trimethyl benzene, 1,3,5-trimethyl benzene,toluene, xylene, cumene, 1,4-dioxane, chloroform, diethyl ether, methylesters of fatty acids (biodiesel), and diethylene glycol butyl ether.Suitable bases include, but are not limited to, sodium hydroxide andpotassium hydroxide. Suitable wetting agents include, but are notlimited to, sodium dioctyl sulfosuccinic acid and sodium dodecylbenzenesulfonic acid. Suitable dispersants include adducts of at least onemono- or polycarboxylic acid or anhydride and an acylating reagent.Suitable acylating reagents include, but are not limited to, fumaricacid, maleic anhydride, maleic acid, succinic anhydride, and succinicacid.

In another embodiment, the C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate may comprise at least one member selected from the groupconsisting of: a) a mixed resin with units of nonylphenol formaldehydealkoxylate and units of butylphenol formaldehyde alkoxylate; b) a resinwith units of nonylphenol formaldehyde alkoxylate; and c) a resin withunits of amylphenol formaldehyde alkoxylate.

In another embodiment, a method of resolving an emulsion present in ahydrocarbon stream is disclosed. The method may comprise contacting thehydrocarbon stream with a demulsifying composition. The demulsifyingcomposition may comprise at least one C₄-C₁₂ alkyl phenol-formaldehyderesin alkoxylate, wherein the C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate has a polymerization number of 2-20 and a degree ofalkoxylation greater than about 30% and less than about 90% relative tothe weight of the resin.

In yet another embodiment, at least one C₄-C₁₂ alkyl phenol-formaldehyderesin alkoxylate may comprise at least two alkyl phenol-formaldehyderesin alkoxylates having different amounts of alkoxylation. The twoalkyl phenol-formaldehyde resin alkoxylates may comprise a first alkylphenol-formaldehyde resin alkoxylate having a percent A by weight ofalkoxylation and a second alkyl phenol-formaldehyde resin alkoxylatehaving a percent B by weight of alkoxylation, wherein A minus B is10-50%. The ratio by weight the first alkyl phenol-formaldehyde resinalkoxylate relative to the second alkyl phenol-formaldehyde resinalkoxylate is 1:9 to 9:1.

In yet another method embodiment, the demulsifying composition may beadded to the hydrocarbon stream in an amount ranging from about 1 toabout 200 ppm by volume of the hydrocarbon stream.

In another embodiment, the demulsifying composition further comprises atleast one polyalkylene oxide polyol with a degree of ethoxylationgreater than about 30% and less than about 85% and a molecular weightranging from about 1000 to about 25,000. The ratio by weight of theC₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylate to the polyalkyleneoxide polyol may range from about 1:9 to about 9:1.

In yet another embodiment, the polyalkylene oxide polyol may comprise atleast two polyalkylene oxide polyols. One of the polyalkylene oxidepolyols may be selected from the group consisting of ethyleneoxide/propylene oxide block polymers, ethylenediamine alkoxylates,polyethylenimine alkoxylates, glycerol alkoxylates, trimethylpropanealkoxylates, and sorbitol alkoxylates. The first polyalkylene oxidepolyol may be an ethylene oxide/propylene oxide block copolymer havingthe formula:

wherein x, y, and z are any integer greater than one, and the moleculehas a molecular weight of 1000-9000. The second polyalkylene oxidepolyol may be an oxide block copolymer having a molecular weight of3000-25000 and 2-6 branches. Each branch may comprise at least onepolyalkoxylate block.

In yet another embodiment, the C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate may comprise at least one member selected from the groupconsisting of: a) a mixed resin with units of nonylphenol formaldehydealkoxylate and units of butylphenol formaldehyde alkoxylate; b) a resinwith units of nonylphenol formaldehyde alkoxylate; and c) a resin withunits of amylphenol formaldehyde alkoxylate.

In another method embodiment, the hydrocarbon stream may comprise crudeoil.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a bar graph showing mean water drop test results forComparative Formulations and Example Formulation 2.1.

FIG. 2 depicts a bar graph showing mean water drop test results forComparative Formulations and Example Formulation 2.1.

FIG. 3 depicts a bar graph showing mean water drop test results forComparative Formulation 2.1 and Example Formulations 2.1A, 2.1B, and2.1C at dosage levels of 4 ppm.

FIG. 4 depicts a bar graph showing mean water drop test results forComparative Formulation 2.1 and Example Formulations 2.1A, 2.1B, and2.1C at dosage levels of 2 ppm.

FIG. 5 depicts a bar graph showing mean water drop test results forComparative Formulation 2.1 and Example Formulations 2.1A, 2.1B, and2.1C at dosage levels of 2 ppm.

FIG. 6 depicts a bar graph showing mean water drop test results forComparative Formulations 2.1 and 2.4 and Example Formulations 2.1A and2.1C at dosage levels of 6 ppm.

FIG. 7 depicts a bar graph showing performance index at differenttemperatures for Comparative Formulations 2.1 and 2.4 and ExampleFormulations 2.1A and 2.1C.

FIG. 8 depicts a graph showing water drop test results with respect totime on a Canadian Crude and American Shale Oil Blend for ComparativeFormulation 3.1 and Example Formulations 3.1, 3.2, 3.3 and 3.4.

FIG. 9 depicts a bar graph showing mean water drop test results forComparative Formulation 3.1 and Example Formulations 3.1, 3.2, 3.3 and3.4.

FIG. 10 depicts a graph showing water drop test results with respect totime on Canadian crude oil for Comparative Formulation 3.1 and ExampleFormulations 3.1, 3.2, 3.3 and 3.4.

FIG. 11 depicts a bar graph showing mean water drop test results forComparative Formulation 3.1 and Example Formulations 3.1, 3.2, 3.3 and3.4.

FIG. 12 depicts a graph showing water drop test results with respect totime on Venezuelan heave crude oil in Example Set 3.

FIG. 13 depicts a bar graph showing mean water drop test results forvarious demulsifier and/or dispersant treatments in Example Set 3.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

It was surprisingly discovered that blends of one or more C₄-C₁₂ alkylphenol-formaldehyde resin alkoxylates produced a robust demulsifyingcomposition that was effective at resolving emulsions in a variety ofcrude types. Specifically, these demulsifying compositions were moreeffective than current formulations in resolving emulsions in some typesof heavy crudes. For example, embodiments of the demulsifyingcomposition are particularly effective on crudes or crude blends with anAmerican Petroleum Institute (“API”) gravity ranging from about 22 to 40(degrees). The crudes or crude blends may comprise greater than, orequal to, about 0.5 wt % asphaltenes. These crudes may also have morethan about 60 pounds of filterable solids per thousand barrels; such as20-500 lbs., or 20-200 lbs., or 60-200 lbs. Exemplary blends for whichthe demulsifying composition is particularly effective include blends ofCanadian crude oils with American shale oils, sweet crudes, or Bakkencrude. The present invention is particularly applicable to oil blendshaving between 1-70%, such as 20-50%, by volume of Western Canada Selectcrudes.

While an organic solvent may be used as part of the formulation, it wasalso surprisingly discovered that water may be used as a solvent for thedemulsifying compositions. Water is generally less expensive than theorganic solvents and alcohols frequently used in demulsifyingcompositions. Accordingly, novel demulsifying compositions are disclosedcomprising ethoxylated surfactants in water. These demulsifyingcompositions are stable as the oil phase does not separate from theaqueous phase.

Without limiting this specification to any particular theory ofoperation, it is thought that the demulsifying compositions with waterare stable because they are colloidal solutions and not true solutionsas previously thought.

Colloidal solutions of surfactants contain micelles. Micelles are groupsof surfactant molecules dispersed in a liquid forming a colloidalsolution. Typically, micelles are spherical with the hydrophilic portionof the surfactant molecules forming the outside of the micelle and thehydrophobic portion filling the micelle's interior. Based upon factorssuch as concentration and temperature as well as the surfactant'schemical structure, other shapes are possible such as rods, tubes, orsheets.

The micelles only form when the concentration of the surfactant in theliquid is greater than the critical micelle concentration (“CMC”). TheCMC may vary depending on the surfactant and the liquid used. Otherfactors that affect the CMC are temperature, pressure, and the presenceof any other compounds that affect the surface tension of the liquid.

Primary emulsion breakers typically have multiple components, including,but not limited to, ethoxylated surfactants in an organic solvent, or“oil”, like naphtha or toluene. An “oil” is any liquid that is solublein another oil or organic solvent, but is not soluble in water. Thus themicelles in primary emulsion breakers are “inverse” micelles because thehydrophobic portion of the surfactant forms the outside of the micelle,and the hydrophilic portion fills the interior. It is thought that whenadded to primary emulsion breakers, aqueous solvents, such as water,enter into the interior of the micelles and “hydrate” the hydrophilic,or polar portion, of the ethylene oxide molecules. The organic solventsmay include aromatic and/or non-aromatic organic solvents.

It was surprisingly discovered, however, that replacing some or all ofthe organic solvents, like naphtha or toluene, with water, resulted instable demulsifying compositions, even though the primary emulsionbreakers may comprise oil-based components. Without limiting theinvention to one theory, it is thought that instead of “inverse”micelles, typical micelles are formed, where the hydrophilic portions ofthe surfactant molecules form the outside of the micelle and thehydrophobic portions, or non-polar regions of the surfactant molecules,fill the micelle's interior. Accordingly, demulsifying compositions andmethods of use are disclosed wherein the demulsifying compositions maycomprise an oil phase and an aqueous phase that form a colloidalmicellar solution.

The present invention is directed to a demulsifying composition and amethod of resolving an emulsion in a hydrocarbon stream with suchdemulsifying composition. Accordingly, in one embodiment, a method ofresolving an emulsion present in a hydrocarbon stream is disclosed. Themethod may comprise contacting the hydrocarbon stream with ademulsifying composition to coalesce aqueous droplets from the emulsionto form an aqueous stream. The aqueous stream may then be removed.

The demulsifying composition may comprise one or more C₄-C₁₂ alkylphenol-formaldehyde resin alkoxylates, each of which may be individuallyreferred to herein as a “demulsifying resin” and collectively as“demulsifying resins”. In one embodiment, the demulsifying compositionmay comprise at least one C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate, an oil phase, and an aqueous phase, wherein the oil andaqueous phases form a colloidal micellar solution. In anotherembodiment, the C₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylate mayhave a polymerization number of 2-20 and a degree of alkoxylationgreater than about 30% and less than about 90% relative to the weight ofthe resin.

In yet another embodiment, the demulsifying composition may comprise 0.1wt % to about 90 wt % water based on a total weight of the demulsifyingcomposition. Alternatively, the demulsifying composition may comprise0.1 wt % to about 30 wt % water based on a total weight of saiddemulsifying composition.

The demulsifying composition may comprise multiple demulsifying resins.Each demulsifying resin may be a C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate, such as a C₅-C₉ alkyl phenol-formaldehyde resin alkoxylate,and may be present in from 1-20%, such as 3-11%, of the weight of thedemulsifying composition. Each alkyl phenol formaldehyde resinalkoxylate may be present in the demulsifying composition at or aboveits critical micelle concentration.

Each demulsifying resin may contain 30-90% alkoxylate by weight, such as35-85, 50-85%, 60-85%, 80-85%, 35-60%, or 50-55% alkoxylate by weight.Each demulsifying resin may have a polymerization number (i.e. thenumber of alkyl phenol formaldehyde units) of 2-20, 2-9, 2-8, 6-8, 8-9,or 9. The alkoxylate portion can include ethylene oxide (“EO”) units,propylene oxide (“PO”) units, or a mixture of EO and PO units, but EOunits are preferred. The demulsifying resin is preferably nonylphenolformaldehyde resin alkoxylate and is more preferably nonylphenolformaldehyde resin ethoxylate.

In yet another embodiment, the demulsifying composition may comprise atleast two different demulsifying resins. The two different demulsifyingresins may differ in terms of the degree of polymerization, amount ofalkoxylation, the type of alkyl phenol, etc. For example, the two alkylphenol-formaldehyde resin alkoxylates may comprise a first alkylphenol-formaldehyde resin alkoxylate, having a percent A by weight ofalkoxylation, and a second alkyl phenol-formaldehyde resin alkoxylate,having a percent B by weight of alkoxylation, wherein A minus B is10-50%. The ratio by weight of the first alkyl phenol-formaldehyde resinalkoxylate relative to the second alkyl phenol-formaldehyde resinalkoxylate may be 1:9 to 9:1. Thus, there may be a difference inalkoxylation where one of the demulsifying resins has an alkoxylationthat is 50-85%, 60-85%, or 80-85% of the weight of the molecule, whilethe other demulsifying resin has an alkoxylation that is 30-60%, or35-60%, or 50-55% of the weight of the molecule. Preferably, thedifference in alkoxylation between a first demulsifying resin and asecond demulsifying resin ranges from 10-50%, or any range within thisrange, such as 25-30%. Thus, if one resin has 85% alkoxylation, and theother one has 35% alkoxylation, then the difference is 50%. If onedemulsifying resin has 60% alkoxylation and the other has 50%, then thedifference is 10%. Similarly, if one has 85% alkoxylation and the otherone has 55%, then the difference is 30%, and if one has 80% and theother has 55%, then the difference is 25%. By using two differentdemulsifying resins with a different amount of alkoxylation, asidentified above, the performance of the demulsifying composition isimproved, particularly with the types of crude oils mentioned above.Each of the two demulsifying resins would be used as 1-20%, or morepreferably, 3-11% by weight of the demulsifying composition. The ratioof the amount of one demulsifying resin to the other may be 1:9 to 9:1,1:3 to 3:1, and 1:1. As stated above, the preferred alkoxylation is withEO and/or PO. The two resins may be used in the demulsifying compositionat or above their critical micelle concentration. At least one of thedemulsifying resins may be a nonylphenol formaldehyde resin alkoxylatewith a degree of polymerization of about 8-9 and about 55% ethyleneoxide by weight.

The amount of the demulsifying composition used will vary withrefineries and the amount of emulsification present in the hydrocarbonstream. Accordingly, in another method, the demulsifying composition maybe added to the hydrocarbon stream in an amount ranging from about 1 toabout 200 ppm by volume of the hydrocarbon stream. Alternatively, thedemulsifying composition may be added to the hydrocarbon stream in anamount ranging from about 1 to about 100 ppm, or about 1 to about 30ppm, or about 2 to about 25 ppm by volume of the hydrocarbon stream.

In another embodiment, the demusifying composition may further compriseat least one polyalkylene oxide polyol with a degree of ethoxylationgreater than about 30% and less than about 85% and a molecular weightranging from about 1000 to about 25,000. The ratio by weight of theC₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylate to the polyalkyleneoxide polyol may range from about 1:9 to about 9:1.

In yet another embodiment, at least one polyalkylene oxide polyol maycomprise two polyalkylene oxide polyols, wherein at least one of thepolyalkylene oxide polyols may be selected from the group consisting ofethylene oxide/propylene oxide block polymers, ethylenediaminealkoxylates, polyethylenimine alkoxylates, glycerol alkoxylates,trimethylpropane alkoxylates, and sorbitol alkoxylates.

In yet another embodiment, the first polyalkylene oxide polyol may be anethylene oxide/propylene oxide block copolymer. The copolymer may havean ethylene oxide (“EO”) and propylene oxide (“PO”) ratio by weightrelative to the total aggregate amount of EO and PO of about 30-50% EOand 50-70% PO, and more preferably 40-50% EO and 50-60% PO. Thus, thecopolymer may be less than about 50% ethylene oxide by weight. In thecopolymer, there are preferably two blocks of EO (EO1 and EO2), and oneblock of PO. The ratio by weight between EO1 and EO2 relative to thetotal aggregate amount of EO may be 30-70% EO1 and 30-70% EO2,preferably 45-55% EO1 and 45-55% EO2, and most preferably, EO1 is aboutthe same as EO2. The copolymer may have a molecular weight of 1000-9000,preferably from 4000-5000, and usually has an average molecular weight,Mw, less than about 6,000 g/mol.

In another embodiment, the first polyalkylene oxide polyol may be anethylene oxide/propylene oxide block copolymer having the formula:

wherein x, y, and z are any integer greater than one, and the moleculehas a molecular weight of 1000-9000.

The second polyalkylene oxide polyol may be a polyalkylene oxide blockpolymer having a molecular weight of 3000-25000 and 2-6 branches. Eachbranch may comprise at least one polyalkoxylate block. In yet anotherembodiment, the second polyalkylene oxide polyol may have 4-6 branches,most preferably four branches. The polyalkoxylate blocks may be blocksof EO units, and/or PO units, and/or butylene oxide (BO) units. Themolecular weight of the second polyalkylene oxide polyol with two ormore branches with polyalkoxylate blocks may be 3000-25000, orpreferably 4000-10500, or more preferably 4700-7000. The secondpolyalkylene oxide polyol may contain at least one block of EO units andat least one block of PO units on each of its 2-6 branches. Preferably,each of these branches includes only one block of EO units and one blockof PO units. Also preferably, the PO blocks are closer to the branchpoint than the EO blocks. The second polyalkylene oxide polyol with twoor more branches may be included in the demulsifying composition in anamount of 0.5% to 10%, or preferably 1% to 4% weight relative to thetotal demulsifying composition.

Examples of the second polyalkylene oxide polyol with two or morebranches with polyalkoxylate blocks may include block copolymers basedon ethylenediamine, propylenediamine, diethylenetriamine, ortriethylenetetramine. Examples of these types of copolymers areethylenediamine ethylene oxide/propylene oxide copolymer,propylenediamine ethylene oxide/propylene oxide copolymer,diethylenetriamine ethylene oxide/propylene oxide copolymer, andtriethylenetetramine ethylene oxide/propylene oxide copolymer.

One example of the second polyalkylene oxide polyol with two or morebranches may have the formula:

where x1, x2, x3, and x4 may be the same or different and represent thenumber of polyethylene oxide units and where y1, y2, y3, and y4 may bethe same or different and represent the number of polypropylene oxideunits, and where the molecular weight is from about 3000-25000. Theratio of the polyethylene oxide units to polypropylene oxide units mayrange from 10:90 to 90:10, or 50:50 to 30:70, and may be about 30:70 orabout 50:50. The ethylenediamine ethylene oxide/propylene oxidecopolymer may have about 40% EO by weight and an average molecularweight, Mw, of about 6,700.

In other embodiments, the demulsifying composition may further compriseone or more aqueous or oil-based crude oil treatments or additives toaid in demulsification or provide other advantages. Accordingly, theaqueous phase may comprise one or more components, including, but notlimited to a pH adjuster, a water-soluble surfactant, a wetting agent, ametal complexing agent, a reverse emulsion breaker, or a corrosioninhibitor. Some of these components are described in other portions ofthis disclosure in more specificity. It is also anticipated that theaqueous phase of the demulsifying composition may comprise one or morewater-soluble additives that aid in demulsification or provide otheradvantages.

In one embodiment, the aqueous phase may comprise a water-soluble pHadjusting agent. The pH adjusting agent may be a base or an acid. The pHadjusting agent may be present in an amount ranging from about 0.5 wt %to about 10 wt % of a total weight of the demulsifying composition.Alternatively, the pH adjusting agent may be present in an amountranging from about 0.5 wt % to about 3 wt % of a total weight of thedemulsifying composition. Suitable bases may be hydroxide bases of GroupIA and IIA metals. In one embodiment the hydroxide base may be sodium orpotassium hydroxide. In another embodiment, the pH adjuster may be anorganic acid, mineral acid, or a carboxylic acid. Examples of suitableacids include, citric acid, propane-1,2,3-tricarboxylic acid, glycolicacid, formic acid, acetic acid, propanoic acid, butanoic acid, pentanoicacid, oxalic acid, glutaric acid, succinic acid, malonic acid, ascorbicacid, and lactic acid. Citric acid has the added advantage in that isalso a metal complexing agent and may reduce the amount of metals in thestream being treated. The pH adjusting agent, such as the hydroxidebases, may be added in effective amounts such that the demulsifyingcomposition will result in a pH of 6-8.

The corrosion inhibitor, such as a water soluble corrosion inhibitor,may comprise at least one member selected from the group consisting ofamidoethyl imidazoline, hydroxyethyl imidazoline, and aminoethylimidazoline. The corrosion inhibitor may be present at about 0.5 wt % toabout 10 wt % based on a total weight of the demulsifying composition.Alternatively, the corrosion inhibitor may be present at about 0.5 wt %to about 5 wt % based on a total weight of the demulsifying composition.

In another embodiment, the aqueous phase may comprise one or morewetting agents like sulfonates and their acids. Suitable sulfonatesinclude, but are not limited to, sodium dioctyl sulfosuccinate andsodium dodecylbenzene sulfonate and acids thereof. In anotherembodiment, the demulsifying composition may further comprise, byweight, 0.5-20%, or preferably, 1-10% of a wetting agent, such asdodecylbenzene sulfonic acid.

Reverse emulsion breakers are materials that aid in flocculation orcoalescence of crude-oil in water emulsions. As such, reverse emulsionbreakers may be categorized as flocculants or coagulants. The reverseemulsion breaker may include one or more inorganic coagulants, such ashydrated chlorides and sulfates. Suitable hydrated chlorides include,but are not limited to, aluminum chloride, aluminum chlorohydrate, ironchloride, and zinc chloride. Suitable sulfates include, but are notlimited to, aluminum sulfate, and iron sulfate. These coagulants can beused by themselves or in combination with other coagulants and/or withflocculants. For example, the reverse emulsion breaker may comprisealuminum chlorohydrate and polydiallyldialkylammonium chloride such aspoly(diallyldimethylammonium chloride). The poly(diallyldialkylammoniumchloride) may have a molecular weight of about 20,000 to about 500,000,such as about 100,000. The weight ratio of aluminum chlorohydrate topoly(diallyldimethylammonium chloride) may be about 1:10 to about 100:1,or about 3:1 to 15:1, or about 9:1. Other cationic polymers can be usedin conjunction with the aluminum chlorohydrate.

Cationic polymers can also be used as coagulants and flocculants.Cationic polymeric coagulants typically have a molecular weight that isless than 1 million, such as 20,000 to 500,000 or 30,000 to 300,000.Cationic polymeric flocculants typically have a molecular weight whichup to 15 million, such as 2-15 million, or 5-15 million, or 2-12million, or 3-9 million.

Cationic polymeric coagulants include several categories, includingquaternized starches, melamine formaldehyde polymers, tannin-basedpolymers, dialkyldiallylammonium polymers, and polyamines, and they havethe molecular weights mentioned above. Tannins can be used by themselvesor they can be combined with other structures, resulting in, forexample, acryloyloxyethyl trimethyl ammonium chloride/tannin polymers.Dialkyldiallylammonium polymers can include but are not limited to,polydiallyldimethylammonium chloride, polydiethyldiallyl ammoniumchloride, polydimethyl diallyl ammonium bromide, and polydi-ethyldiallyl ammonium bromide.

The polyamines can be one or a combination of molecules exemplified bythe formula below:

where R_(A), R_(B), R_(C), and R_(D) may be, independently, the same ordifferent and are H, or alkyls of 1 to 20 carbon atoms, preferably 1-8carbon atoms. N ranges from 100 to 50,000. The alkyls may be straightalkyls, branched alkyls, substituted alkyls (such ashydroxyl-substituted alkyls or alkoxy-substituted alkyls), or aryls.Suitable amine monomers include, but are not limited to, dimethylamineand dimethylpropylamine.

Other amines that can be polymerized to form suitable cationic polymersare: dimethylaminopropylamine, 1,4-dimethylpiperazine,N-methylpyrrolidine, di-ethylhydroxylamine, pyrrolidine,N,N,N,N-tetramethylethylenediamine, diethylenetriamine andfurfurylamine.

Cationic polymeric flocculants have the molecular weights mentionedabove, and are usually acrylamide polymers. Examples are polymers ofacrylamide with diallyldimethylammonium chloride oracryloyloxyethyltrimethylammonium chloride or methacryloyloxyethyltrimethyl ammonium chloride or methacryloyloxyethyl trimethyl ammoniummethyl sulfate or acrylamido propyl trimethyl ammonium chloride or3-(methacrylamido) propyl trimethyl ammonium chloride ormethacrylamidopropyltrimethylammonium chloride. However, polymers of thefollowing can also be utilized as cationic polymeric flocculants withoutthe acrylamide: acryloyloxyethyltrimethylammonium chloride ormethacryloyloxyethyl trimethyl ammonium chloride or methacryloyloxyethyltrimethyl ammonium methyl sulfate or acrylamido propyl trimethylammonium chloride or 3-(methacrylamido) propyl trimethyl ammoniumchloride or methacrylamidopropyltrimethylammonium chloride.

Generally, the reverse emulsion breakers can include coagulants and/orflocculants, and may include one or more coagulants and/or one or moreflocculants. The reverse emulsion breaker may be present at about 0.5 wt% to about 10 wt % based on a total weight of the demulsifyingcomposition. Alternatively, the reverse emulsion breaker may be presentat about 0.5 wt % to about 5 wt % based on a total weight of thedemulsifying composition.

In another embodiment, the demulsifying composition may comprise atleast one member selected from the group consisting of an acid, anon-polar organic solvent, a base, a wetting agent, and a dispersant.Suitable acids include, but are not limited to, acetic acid, citricacid, malic acid, maleic acid, succinic acid, glycolic acid, methanesulfonic acid, dodecylbenzenesulfonic acid, naphthalene sulfonic acid,and p-toluene sulfonic acid. Suitable non-polar organic solventsinclude, but are not limited to, naphtha, light aromatic naphtha, heavyaromatic naphtha, pentane, cyclopentane, hexane, cyclohexane, benzene,ethyl benzene, 1,2,4-trimethyl benzene, 1,3,5-trimethyl benzene,toluene, xylene, cumene, 1,4-dioxane, chloroform, diethyl ether, methylesters of fatty acids (biodiesel), and diethylene glycol butyl ether.Suitable bases include, but are not limited to, sodium hydroxide andpotassium hydroxide. Suitable wetting agents include, but are notlimited to sodium dioctyl sulfosuccinic acid and sodium dodecylbenzenesulfonic acid. Suitable dispersants include adducts of at least onemono- or polycarboxylic acid or anhydride and an acylating reagent.Suitable acylating reagents include, but are not limited to, fumaricacid, maleic anhydride, maleic acid, succinic anhydride, and succinicacid. The acid and/or base can be used to adjust pH.

In yet another embodiment, the C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate may comprise at least one member selected from the groupconsisting of: a) a mixed resin with units of nonylphenol formaldehydealkoxylate and units of butylphenol formaldehyde alkoxylate; b) a resinwith units of nonylphenol formaldehyde alkoxylate; and c) a resin withunits of amylphenol formaldehyde alkoxylate.

In yet another embodiment, the demulsifying resin may comprise an adductof at least one C₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylate andthe nonylphenol formaldehyde resin alkoxylate that is at least 50%ethylene oxide by weight. For example, the demulsifying resin may be anadduct of monomers of a nonylphenol formaldehyde resin alkoxylate thatis at least 50% ethylene oxide by weight, such as 50-90% ethylene oxide,or 70-90% ethylene oxide, and monomers of a butylphenol formaldehyderesin alkoxylate that is at least 50% ethylene oxide by weight, such as50-90% ethylene oxide, or 70-90% ethylene oxide by weight. The totaldegree of polymerization for both monomers may be 3-10 or 6-9. The ratioof the number of monomers containing butylphenol versus nonylphenol inthe final resin may be 9:1 to 1:9, or preferably 2:1 to 1:2. Thisparticular resin is appropriate for crudes having an API of 28-40. Theamount of this resin that can be used is 1-20%, preferably 3-11% byweight relative to the demulsifying composition. This resin may be usedby itself or in conjunction with another demulsifying resin described inthe present application. Accordingly, the demulsifying resin maycomprise two different resins, each resin with different alkyl phenolunits. For example, the demulsifying resin may comprise a nonylphenolformaldehyde resin alkoxylate and an amyphenol formaldehyde resinalkoxylate. Alternatively, the demulsifying resin may comprise differentalkyl phenol units, such as nonylphenol and butylphenol, within oneresin.

In another embodiment, at least one C₄-C₁₂ alkyl phenol-formaldehyderesin alkoxylate may be a nonylphenol formaldehyde resin alkoxylate thatis at least 50% ethylene oxide by weight. In another embodiment, atleast one C₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylate may be anonylphenol formaldehyde resin alkoxylate with a degree ofpolymerization of about 8-9 and is about 55% ethylene oxide by weight.In another embodiment, the C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate may be amyl phenol-formaldehyde resin alkoxylate.

In another method, the hydrocarbon stream may comprise crude oil. In yetanother method the emulsion may be resolved in a desalter of a crude oilrefinery. The demulsifying composition may be added to the desalter orupstream of the desalter (i.e., to the crude oil before it enters thedesalter). In another embodiment, the demulsifying composition may beadded right before the mixing valve upstream of the desalter. It is alsopossible to add the demulsifying composition to the wash water of thedesalter, particularly if the demulsifying composition contains water.

In yet another method, the oil phase may comprise at least one non-polarorganic solvent. Suitable non-polar organic solvents include, but arenot limited to, naphtha, light aromatic naphtha, heavy aromatic naphtha,pentane, cyclopentane, hexane, cyclohexane, benzene, ethyl benzene,1,2,4-trimethyl benzene, toluene, xylene, cumene, 1,4-dioxane,chloroform, diethyl ether, methyl esters of fatty acids (biodiesel), anddiethylene glycol butyl ether (butyl carbitol).

In another method, the demulsifying composition may comprise an aqueoussolvent. The aggregate amount of solvent, whether organic or aqueous,may be about 10% to 90%, such as 40-90% or 10-75%, or 50-85%, and ispreferably 55-75% by weight of the demulsifying composition. The oilphase and the aqueous phase in the demulsifying composition may form acolloidal micellar solution. Any ratio of organic solvent to aqueoussolvent is within the scope of the present invention, with the extremesbeing 100% aqueous solvent or 100% organic solvent relative to theamount of solvent. Preferably, the ratio of aqueous solvent to organicsolvent is 90:10 to 70:30.

In another method embodiment, the demulsifying composition may furthercomprise a coupling agent or stabilizer, to further stabilize thedemulsifying composition and prevent the phase separation. Suitablestabilizers include, but are not limited to, diethylene glycol butylether, hexylene glycol, methyl cellosolve (2-methoxyethanol), butanol,and octanol. The coupling agent or stabilizer may be present in anamount of 5-50%, such as 5-25%, and such as 5-20% of the demulsifyingcomposition. The coupling agent may be an organic solvent, an examplebeing diethylene glycol butyl ether (i.e. butyl carbitol). Accordingly,in another embodiment, the demulsifying composition may further comprisediethylene glycol butyl ether.

In another embodiment, a dispersant, such as an alkyl succinic anhydridebased material, may be used in conjunction with the demulsifyingcomposition to improve performance. The alkyl succinic anhydride basedmaterial may be a polyisobutenyl succinic anhydride based material.While a polyisobutenyl succinic anhydride-based material may have beenused as an antifoulant for crude oil, such as in upstream applications,this material has special properties that will work conjunctively withthe demulsifying composition to better resolve emulsions in downstreamapplications. Asphaltenes in the crude oil are believed to havehydrophilic functionalities which may result in a colloidal aggregationor flocculation of the asphaltenes at the interface of the aqueous phaseand oil phase in a desalter. These hydrophilic functionalities decreasethe ability of the dispersed phases to migrate towards respectivecontinuous phases to resolve the emulsion. Thus, asphaltenes makeresolving emulsions in a desalter difficult. The polyisobutenyl succinicanhydride based material is believed to adsorb onto the asphaltenes anddecrease the colloidal aggregation or flocculation and deposition of theasphaltenes at the oil-water interface, thereby accelerating the speedat which the emulsion may be resolved by the demulsifying composition.The polyisobutenyl succinic anhydride based material may be addedtogether with the demulsifying composition or separately, such asupstream of the addition of the demulsifying composition. The advantageof the separate addition is that the addition may be selective forcrudes which have an asphaltene content of 0.5% or more, such as 0.5% to50%, or 0.5% to 10%, or 0.5% to 8%.

The dispersant may be an ester that is a mono- or polycarboxylic acid oranhydride that has been treated with an acylating reagent. The mono- orpolycarboxylic acid ester may have at least one moiety that is a polyolas shown in any of the following three formulas:

where R¹, R², R³, and R⁴ are the same or different and are selected fromthe group consisting of H, an alkyl, and CH(OH)(R⁵); wherein R⁵ is H orC₁ to C₁₀ alkyl; and wherein X and Y are the same or different and are Hor C₁ to C₁₀ alkyl, with the proviso that at least one of R², R³, and R⁴is the CH(OH)(R⁵) moiety. Suitable alkyls may be polyalkenes, includinginterpolymers of various alkenes, and may include, but are not limitedto, ethylene, propene, isoprene, 1-butene, 2-butene, isobutene,3-pentene, 1-hexene, 1-octene, 4-octene, 2-methyl-1-heptene,3-cyclohexyl-1-butene, 2-methyl-5-propyl-1-hexene, styrene, butadiene,and piperylene. The —CH(OH)(R⁵) moiety may be mono or polyhydricalcohols, preferably polyhydric, such as glycerol, erythritol,pentaerythritol, mannitol, and sorbitol.

The acylating reagent may be aliphatic mono- or polycarbocylic acids,anhydrides, or halides. Suitable acylating reagents may include, but arenot limited to, fumaric acid, maleic anhydride, maleic acid, succinicanhydride, and succinic acid.

In a preferred embodiment, the acid ester has a polyisobutenyl andpentaerythritol moiety and has been treated with succinic anhydride orsuccinic acid such that the dispersant is a polyisobutenyl succinicanhydride ester (“PiBS ester”) with a polyol moiety as in the followingformula:

wherein R is a polyisobutenyl moiety.

Accordingly, in another embodiment, an alkyl succinic anhydride basedmaterial, such as a polyisobutenyl succinic anhydride based material maybe used as the dispersant. The dispersant, such as the polyisobutylenylsuccinic anhydride based material may be added to the desalter orupstream of the desalter in an amount of 1-1000 ppm, or 2-200 ppm, ormore preferably, 20-200 ppm by volume of the hydrocarbon stream.

The polyisobutenyl succinic anhydride based material may be apolyisobutenyl succinic anhydride derived ester with a molecular weight,Mw, of about 20,000 to about 25,000 in an aromatic solvent. The %actives may range from about 10-50% and the solvent may be aromaticnaphtha.

In another embodiment, a demulsifying composition for treating ahydrocarbon stream is provided. The demulsifying composition maycomprise at least one C₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylate,an oil phase, and an aqueous phase, wherein the oil and aqueous phasesform a colloidal micellar solution. The demulsifying composition maycomprise 0.1 wt % to about 90 wt % water based on a total weight of saiddemulsifying composition.

In another embodiment, the C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate may have a polymerization number of 2-20 and a degree ofalkoxylation greater than about 30% and less than about 90% relative tothe weight of the resin. In yet another embodiment, the demulsifyingcomposition comprises 0.1 wt % to about 30 wt % water based on a totalweight of said demulsifying composition.

In another embodiment, the C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate comprises at least two alkyl phenol-formaldehyde resinalkoxylates having different amounts of alkoxylation. The two alkylphenol-formaldehyde resin alkoxylates may comprise a first alkylphenol-formaldehyde resin alkoxylate, having a percent A by weight ofalkoxylation, and a second alkyl phenol-formaldehyde resin alkoxylate,having a percent B by weight of alkoxylation, wherein A minus B is10-50%. The ratio by weight of an amount of the first alkylphenol-formaldehyde resin alkoxylate relative to the second alkylphenol-formaldehyde resin alkoxylate may be 1:9 to 9:1.

In yet another embodiment, the demulsifying composition may furthercomprise at least one polyalkylene oxide polyol with a degree ofethoxylation greater than about 30% and less than about 85% and amolecular weight ranging from about 1000 to about 25,000. The ratio byweight of the C₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylate to thepolyalkylene oxide polyol may range from about 1:9 to about 9:1. Inanother embodiment, the polyalkylene oxide polyol may comprise twopolyalkylene oxide polyols, wherein one of the polyalkylene oxidepolyols may be selected from the group consisting of ethyleneoxide/propylene oxide block polymers, ethylenediamine alkoxylates,polyethylenimine alkoxylates, glycerol alkoxylates, trimethylpropanealkoxylates, and sorbitol alkoxylates.

In yet another embodiment, the first polyalkylene oxide polyol may be anethylene oxide/propylene oxide block copolymer having the formula:

wherein x, y, and z are any integer greater than one, and the moleculehas a molecular weight of 1000-9000. The second polyalkylene oxidepolyol may be an oxide block copolymer having a molecular weight of3000-25000 and 2-6 branches. Each branch may comprise at least onepolyalkoxylate block.

In another embodiment, the aqueous phase may further comprise awater-soluble reverse emulsion breaker and/or a water-soluble corrosioninhibitor, as described above.

In another embodiment, the demulsifying composition may further compriseat least one member selected from the group consisting of an acid, anon-polar organic solvent, a base, a wetting agent, and a dispersant.Suitable acids include, but are not limited to, acetic acid, citricacid, malic acid, maleic acid, succinic acid, glycolic acid, methanesulfonic acid, dodecylbenzenesulfonic acid, naphthalene sulfonic acid,and p-toluene sulfonic acid. Suitable non-polar organic solventsinclude, but are not limited to, naphtha, light aromatic naphtha, heavyaromatic naphtha, pentane, cyclopentane, hexane, cyclohexane, benzene,ethyl benzene, 1,2,4-trimethyl benzene, 1,3,5-trimethyl benzene,toluene, xylene, cumene, 1,4-dioxane, chloroform, diethyl ether, methylesters of fatty acids (biodiesel), and diethylene glycol butyl ether.Suitable bases include, but are not limited to, sodium hydroxide andpotassium hydroxide. Suitable wetting agents include, but are notlimited to, sodium dioctyl sulfosuccinic acid and sodium dodecylbenzenesulfonic acid. Suitable dispersants include adducts of at least onemono- or polycarboxylic acid or anhydride and an acylating reagent.Suitable acylating reagents include, but are not limited to, fumaricacid, maleic anhydride, maleic acid, succinic anhydride, and succinicacid.

In another embodiment, the C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate may comprise at least one member selected from the groupconsisting of: a) a mixed resin with units of nonylphenol formaldehydealkoxylate and units of butylphenol formaldehyde alkoxylate; b) a resinwith units of nonylphenol formaldehyde alkoxylate; and c) a resin withunits of amylphenol formaldehyde alkoxylate.

In another embodiment, a method of resolving an emulsion present in ahydrocarbon stream is disclosed. The method may comprise contacting thehydrocarbon stream with a demulsifying composition. The demulsifyingcomposition may comprise at least one C₄-C₁₂ alkyl phenol-formaldehyderesin alkoxylate, wherein the C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate has a polymerization number of 2-20 and a degree ofalkoxylation greater than about 30% and less than about 90% relative tothe weight of the resin.

In yet another method embodiment, the demulsifying composition may beadded to the hydrocarbon stream in an amount ranging from about 1 toabout 200 ppm by volume of the hydrocarbon stream.

In another method embodiment, the hydrocarbon stream may comprise crudeoil.

EXAMPLES Example Set 1—Stability Tests

For Example Set 1, exemplary demulsifying compositions, Examples 1.1-1.5were prepared and the stability of the colloidal solutions was tested.For Examples 1.1-1.5, 10 wt % of an aqueous phase and 90 wt % of an oilphase were mixed to form a colloidal solution. Table 1 lists anexemplary formulation for the oil phase. The weight percents listed inTable 1 are based on the total weight of the oil phase. The variousaqueous phases for the examples comprised 10 wt % of the total weight ofthe dual phase composition and are listed in Table 2.

TABLE 1 Oil Phase (90 wt % of total) 22.22 wt % amylphenol formaldehyderesin alkoxylate 13.33 wt % oil-soluble EtO/PrO polymer 53.33 wt %naphtha and heavy aromatic solvent blend 11.11 wt % hexylene glycol

The oil phase was then combined with the aqueous phase to form a dualphase composition. The aqueous phases were aqueous solutions formulatedas in Table 2.

TABLE 2 Example Various Aqueous Phases (10 wt % of total) 1.1 1 wt %NaOH in solution 1.2 10 wt % water-soluble EtO/PrO polymer 1.3 10 wt %citric acid in solution 1.4 10 wt % sodium dioctyl sulfosuccinate 1.5 47wt % aluminum chlorohydrate and poly(diallyldimethylammonium chloride)mixture

As listed in Tables 1 and 2, an exemplary dual phase composition,Example 1.1, comprised 20 wt % amylphenol formaldehyde resin alkoxylate,12 wt % of an oil-soluble ethylene oxide/propylene oxide polymer, 48 wt% of a non-polar organic solvent, 10 wt % hexylene glycol, and 0.1 wt %NaOH in solution. These wt % values are based on a total wt % of thedual composition. Exemplary dual phase composition Example 1.2 comprised20 wt % amylphenol formaldehyde resin alkoxylate, 12 wt % of anoil-soluble ethylene oxide/propylene oxide polymer, 48 wt % of anon-polar organic solvent, 10 wt % hexylene glycol, and 1 wt % of awater-soluble ethylene oxide/propylene oxide polymer. Example 1.3comprised 20 wt % amylphenol formaldehyde resin alkoxylate, 12 wt % ofan oil-soluble ethylene oxide/propylene oxide polymer, 48 wt % of anon-polar organic solvent, 10 wt % hexylene glycol, and 1 wt % of acitric acid in solution. Example 1.4 comprised 20 wt % amylphenolformaldehyde resin alkoxylate, 12 wt % of an oil-soluble ethyleneoxide/propylene oxide polymer, 48 wt % of a non-polar organic solvent,10 wt % hexylene glycol, and 1 wt % sodium dioctyl sulfosuccinate.Example 1.5 comprised 20 wt % amylphenol formaldehyde resin alkoxylate,12 wt % of an oil-soluble ethylene oxide/propylene oxide polymer, 48 wt% of a non-polar organic solvent, 10 wt % hexylene glycol, and 4.7 wt %aluminum chlorohydrate and poly(diallyldimethylammonium chloride)mixture.

The resulting dual phase compositions, Examples 1.1 through 1.5, werestable, homogenous mixtures and did not separate when stored at ambienttemperature or at −10° C. for more than 14 days.

Example Set 2—Demulsifying Effectiveness

For the examples in Example Set 2, a desalter process with an electricfield and desalter mix valve was simulated to evaluate the effectvarious emulsion breaker (demulsifier) formulations had on resolvingwater and crude oil emulsions. For these examples, 93 vol % crude oilwas mixed with 7 vol % wash water in a test tube. Then 2 to 4 ppm byvolume of a demulsifier was added to the crude oil and wash watermixture and mixed at 16,000 rpm in a blender for 3 seconds. For thesedimentation step, the mixture was allowed to settle at a temperatureranging from 115 to 130° C. and at an electrical field strength of 10 kVfor residence times of 3, 6, 8, 16, and 32 minutes. A mean water droptest was performed by taking the readings of the volume of water (mL)which had dropped to the bottom of the test tube at each of theresidence times and averaging the readings. The mean water drop testindicates both the speed of water drop and the amount of water that hadseparated from the emulsion. The mean water drop test was repeated withcrude oils of various American Petroleum Institute (“API”) gravities andwash waters of various pHs.

Various comparative formulations and exemplary formulations ofemulsifiers were tested. The exemplary formulations were synergisticblend compositions comprising 20-60 wt % (based on a total weight of thecomposition) of a C₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylate witha degree of ethoxylation greater than about 60% and less than about 90%;2-20 wt % of a polyalkylene oxide polyol with a degree of ethoxtylationgreater than about 30% and less than about 85%; and 1-10 wt % of anorganic acid.

More specifically, the synergistic blend compositions comprised anonylphenol-formaldehyde resin ethoxylate, with an average molecularweight of about 6,000 to 8,000 and a degree of ethoxylation of about 85%to 90% and; a nonylphenol-formaldehyde resin ethoxylate, with an averagemolecular weight of about 800 to about 1,500 with a degree ofethoxylation of about 70% to 80%; a polyalkylene oxide polyol, with adegree of ethoxylation of about 80% and an average molecular weight ofabout 8,400; a polyalkylene oxide polyol, with a degree of ethoxylationof about 40% and an average molecular weight of about 4,200; and atleast one organic acid.

Comparative Formulation 2.1 (“Comp 2.1”)

For Comp 2.1, a mixture of a C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate, with a degree of ethoxylation of about 50%, and an ethyleneoxide/propylene oxide block copolymer, with a degree of ethoxylation ofabout 40%, was used as the demulsifier.

Comparative Formulation 2.2 (“Comp 2.2”)

For Comp 2.2, a nonylphenol-formaldehyde resin ethoxylate, with a degreeof ethoxylation of about 85% to 90% and an average molecular weight ofabout 6,000 to about 8,000, was used as the demulsifier.

Comparative Formulation 2.3 (“Comp 2.3”)

For Comp 2.3, a nonylphenol-formaldehyde resin ethoxylate, with a degreeof ethoxylation of about 70% to 80%, and an average molecular weight ofabout 800 to about 1,500, was used as the demulsifier.

Example Formulation 2.1 (“Example 2.1”)

For Example 2.1, the synergistic blend composition listed in Table 3 wasused.

TABLE 3 Example 2.1 wt % nonylphenol-formaldehyde resin ethoxylate(85%-90% EO) 10 nonylphenol-formaldehyde resin ethoxylate (70%-80% EO)10 EO/PO block copolymer (40% EO) 5 EO/PO block copolymer (80% EO) 5dodecylbenzenesulfonic acid 1 Water 69

FIG. 1 shows mean water drop test results for the ComparativeFormulations and Example Formulation 2.1. No demulsifier was added tothe “Blank” sample. The crude oil used had an API ˜27. The wash waterhad a pH of 7.2. The test temperature was 130° C.

FIG. 2 shows mean water drop test results for the ComparativeFormulations and Example Formulation 2.1. No demulsifier was added tothe “Blank” sample. The crude oil used had an API ˜27. The pH of thewash water was adjusted to a pH of 9.4 with a solution comprising 10 wt% NaOH and 25 wt % ammonia. The test temperature was 130° C.

Additional synergistic blend compositions, Examples 2.1A, Example 2.1B,and Example 2.1C were also tested. Their compositions are listed inTables 4-6.

TABLE 4 Example 2.1A wt % nonylphenol-formaldehyde resin ethoxylate(85%-90% EO) 10 nonylphenol-formaldehyde resin ethoxylate (70%-80% EO)10 EO/PO block copolymer (40% EO) 5 EO/PO block copolymer (80% EO) 5dodecylbenzenesulfonic acid 1 citric acid 2 Water 67

TABLE 5 Example 2.1B wt % nonylphenol-formaldehyde resin ethoxylate(85%-90% EO) 13.5 nonylphenol-formaldehyde resin ethoxylate (70%-80% EO)6.5 EO/PO block copolymer (40% EO) 7 EO/PO block copolymer (80% EO) 3dodecylbenzenesulfonic acid 1 citric acid 2 Water 67

TABLE 6 Example 2.1C wt % nonylphenol-formaldehyde resin ethoxylate(85%-90% EO) 15 nonylphenol-formaldehyde resin ethoxylate (70%-80% EO) 5EO/PO block copolymer (40% EO) 7 EO/PO block copolymer (80% EO) 3dodecylbenzenesulfonic acid 1 citric acid 2 Water 67

FIG. 3 shows mean water drop test results for the ComparativeFormulation 2.1 and Example Formulations 2.1A, 2.1B, and 2.1C at dosagelevels of 4 ppm. No demulsifier was added to the “Blank” sample. Thecrude oil used had an API 32. The pH of the wash water was 6.7. The testtemperature was 125° C.

FIG. 4 shows mean water drop test results for the ComparativeFormulation 2.1 and Example Formulations 2.1A, 2.1B, and 2.1C at dosagelevels of 2 ppm. The crude oil used had an API ˜32. The pH of the washwater was 6.7. The test temperature was 125° C.

FIG. 5 shows mean water drop test results for the ComparativeFormulation 2.1 and Example Formulations 2.1A, 2.1B, and 2.1C at dosagelevels of 2 ppm. No demulsifier was added to the “Blank” sample. Thecrude oil used had an API 35. The pH of the wash water was 7.2. The testtemperature was 115° C.

Example Set 2—Demulsifying Effectiveness at Different Temperatures

To test the demulsifying effectiveness at different temperatures, adesalter process was simulated as described above. However, thesedimentation step was repeated at 3 different temperatures, 130, 100,and 60° C. The mean water drop test was performed at all threetemperatures.

Comparative Formulation 2.4 (“Comp 4”)

For Comp 2.4, an EO/PO block copolymer with a degree of ethoxylation ofabout 80% was used as the demulsifier.

FIG. 6 shows mean water drop test results for the ComparativeFormulations 2.1 and 2.4 and Example Formulations 2.1A and 2.1C atdosage levels of 6 ppm. No demulsifier was added to the “Blank” sample.

FIG. 7 shows the performance index at different temperatures for theemulsions tested in Example Set 2 and shown in FIG. 6 . To calculate theperformance index, the demulsifier performance was first rated based ona visual observation of each test tube. This performance test is calledthe Water Clarity Index (“WCI”). If the separated water is clear, orfree from oil, and the oil-water interface is sharp (i.e. no rag ispresent) then the demulsifier is given a rating of a 5. Less effectivedemulsifiers are rated lower than 5. Ineffective demulsifiers are givena value of 1. The WCI is then multiplied by the mean water drop tocalculate the performance index.

Example Set 3—Effectiveness on Different Sources of Crude

Additional exemplary formulations are shown in Table 7. The exemplaryformulations may comprise 10 to 40% actives with the remainder of theformulations comprising an organic or aqueous solvent or a combinationthereof. The actives may include a polyalkylene oxide triblock polyolwith about 40% EO by weight and an average molecular weight, Mw of about4,200 (“EO/PO Surf. 40% EO”) and at least one alkyl phenol-formaldehyderesin alkoxylate. The EO/PO Surf. 40% EO may be present in an amountranging from about 10 wt % to about 50 wt % based on a combined weightof the alkyl phenol-formaldehyde resin alkoxylate and the EO/PO Surf.

Suitable alkyl phenol-formaldehyde resin alkoxylates include nonylphenolformaldehyde resin alkoxylates (“NPF”) and/or amylphenol formaldehyderesin alkoxylates (“APF”) with a degree of polymerization ranging fromabout 4 to about 12 and are about 40% to about 80% ethylene oxide byweight. As shown in Table 7, one such APF may be an amylphenolformaldehyde resin alkoxylate with a degree of polymerization of about7-8 and is about 40% ethylene oxide by weight (“APF 40% EO”). Also shownin Table 7 are suitable NPF. One such NPF may be a nonylphenolformaldehyde resin alkoxylate with a degree of polymerization of about6-7 and is about 50% ethylene oxide by weight (“NPF 50% EO”). AnotherNPF may be a nonylphenol formaldehyde resin alkoxylate with a degree ofpolymerization of about 8-9 and is about 55% ethylene oxide by weight(“NPF 55% EO”). Another suitable NPF may be a nonylphenol formaldehyderesin alkoxylate with a degree of polymerization of about 2-8 and isabout 80% ethylene oxide by weight (“NPF 80% EO”). The alkylphenol-formaldehyde resin alkoxylates may also be adducts of at leasttwo alkyl phenol-formaldehyde resin alkoxylates. In one embodiment, theadduct may be an adduct of a nonylphenol formaldehyde resin alkoxylatethat is at least 50% ethylene oxide by weight and a butylphenolformaldehyde resin alkoxylate that is at least 50% ethylene oxide byweight (“NPF/BPF”). In other words, the NPF/BPF is a mixed resin withunits of both nonylphenol formaldehyde alkoxylate and butylphenolformaldehyde alkoxylate.

The actives may also comprise one or more aqueous or oil-based crude oiltreatments or additives to aid in demulsification. One such additive maybe an ethylenediamine ethylene oxide/propylene oxide copolymer withabout 40% EO by weight and an average molecular weight, Mw, of about6,700 (“ED EO/PO”). The ED EO/PO may be present in an amount rangingfrom about 1 to about 10 wt % of a total weight of the demulsifyingcomposition. Alternatively, the ED EO/PO may be present in an amountranging from about 2 to about 4 wt % of a total weight of thedemulsifying composition.

Another additive example is a wetting agent such as dodecylbenzenesulfonic acid (“DDBSA”). In one embodiment, the DDBSA may be present inan amount ranging from about 1 to about 10 wt % of a total weight of thedemulsifying composition. Alternatively, the DDBSA may be present in anamount ranging from about 2 to about 4 wt %.

TABLE 7 DEMULSIFIER FORMULATIONS Raw Materials (wt %) Actives APF NPFEO/PO Solvents 40% NPF 55% 80% ED Surf. Heavy EO EO EO NPF/BPF EO/PO 40%EO DDBSA Naph. C₈H₁₈O₃ H₂O Ex A 10.70 10.70 3.43 5.14 55.03 15.00 Ex B7.13 7.13 2.29 3.43 65.02 15.00 Ex C 7.14 7.14 2.29 3.43 20.00 60.00 ExD 3.57 3.57 1.15 1.71 20.00 70.00 Ex E 7.14 7.14 2.29 4.43 3.00 15.0062.00 Ex F 3.57 3.57 1.15 1.71 3.00 15.00 72.00 Ex G 7.14 7.14 2.29 3.4320.00 60.00 Ex H 3.57 3.57 1.15 1.71 20.00 70.00 Ex I 7.14 7.14 2.293.43 3.00 15.00 62.00 Ex J 3.57 3.57 1.15 1.71 3.00 15.00 72.00 Ex K22.50 7.50 5.00 65.00 Ex J 22.50 7.50 5.00 5.00 60.00 Note: C₈H₁₈O₃ isdiethylene glycol butyl ether (butyl carbitol)

The efficacy of similar demulsifying formulations was tested on U.S. andCanadian crude oils. The formulations tested are listed in Table 8.

All the formulations in Table 8 comprised a surfactant that was apolyalkylene oxide triblock polyol with about 40% EO by weight and anaverage molecular weight, Mw of about 4,200 (“EO/PO Surf. 40% EO”) andat least one alkyl phenol-formaldehyde resin alkoxylate (see Table 8).Comparative example 3.2 (Comp 3.2″) comprised an amylphenol formaldehyderesin alkoxylate with a degree of polymerization of about 7-8 and wasabout 40% EO by weight (“APF 40% EO”). All the rest of the formulationstested comprised at least one nonylphenol formaldehyde resin alkoxylate(“NPF”). The first NPF was a nonylphenol formaldehyde resin alkoxylatewith a degree of polymerization of about 6-7 and was about 50% ethyleneoxide by weight (“NPF 50% EO”). The second NPF was a nonylphenolformaldehyde resin alkoxylate with a degree of polymerization of about8-9 and was about 55% ethylene oxide by weight (“NPF 55% EO”). The thirdNPF was a nonylphenol formaldehyde resin alkoxylate with a degree ofpolymerization of about 2-8 and was about 80% ethylene oxide by weight(“NPF 80% EO”).

Comparative examples 3.1 and 3.2 (“Comp 3.1” and “Comp 3.2”respectively) have no water in the formulations. Comp 3.2 also comprisedan oil-soluble surfactant that was a polyalkylene oxide triblock polyolwith about 10% EO and an average molecular weight, Mw of about 4,400(“EO/PO Surf. 10% EO”).

The resulting formulations, Examples 3.1 through 3.4 (i.e. Ex 3.1-Ex3.4), all had water in the formulations and were stable, micellarsolutions that did not separate when stored at ambient temperature formore than 30 days. Examples 3.1 through 3.4 also included anethylenediamine ethylene oxide/propylene oxide copolymer (“ED EO/PO”)that was about 40% EO by weight and had an average molecular weight, Mw,of about 6,700.

TABLE 8 DEMULSIFIER FORMULATIONS Raw Materials (wt %) Actives APF NPFNPF NPF EO/PO EO/PO Solvents 40% 50% 55% 80% ED Surf. Surf. Heavy LightEO EO EO EO EO/PO 10% EO 40% EO Naph. Naph. C₆H₁₄O₂ C₈H₁₈O₃ H₂O Comp27.0 23.5 4.5 45.0 3.1 Comp 28.0 6.0 6.0 30.0 20.0 10.0 3.2 Ex 3.1 12.512.5 4.0 6.0 55.0 10.0 Ex 3.2 12.5 12.5 4.0 6.0 5.0 60.0 Ex 3.3 12.512.5 4.0 6.0 55.0 10.0 Ex 3.4 12.5 12.5 4.0 6.0 5.0 60.0 Note: C₆H₁₄O₂ishexylene glycol; C₈H₁₈O₃ is diethylene glycol butyl ether (butylcarbitol)

Canadian Crude and American Shale Oil Blend

A desalter process with an electric field and desalter mix valve wassimulated to evaluate the effect the emulsion breaker (demulsifier)formulations in Table 8 had on breaking water and crude oil emulsions.The crude oil used was a blend of Canadian crudes and American shaleoils. The Basic Sediments and Water (“BS&W”) of the crude was about 50pounds of solids per thousand barrels and 0.1 wt % water. Comp 3.1 wasused as the comparative example. For these examples, 95 vol % crude oilwas mixed with 5 vol % wash water (pH=7) in a test tube. Then 3 ppm byvolume of a demulsifier was added to the crude oil and wash watermixture and mixed at 6,000 rpm in a blender for 2 seconds. For thesedimentation step, the mixture was allowed to settle at a temperatureof about 110° C. and at an electrical field strength of 10 kV. Thevolume of free water (mL) was measured at 2, 4, 8, 16, and 32 minutes.

The mean water drop is the average measured volume of free water. Themean water drop indicates both the speed of water drop and the amount ofwater that had separated from the emulsion. The water drop with respectto time for the Canadian Crude and American Shale Oil Blend is shown inFIG. 8 . The mean water drop for the various demulsifier formulationsare shown in FIG. 9 .

Canadian Crude Oil

A desalter process with an electric field and desalter mix valve wassimulated to evaluate the effect the emulsion breaker (demulsifier)formulations in Table 8 had on breaking water and crude oil emulsions.The crude oil used was Canadian crude oil from Sarnia, Ontario. The BS&Wof the crude was about 50 pounds of solids per thousand barrels and 0.1wt % water. Comp 3.2 was used as the comparative example. For theseexamples, 95 vol % crude oil was mixed with 5 vol % wash water (pH=7) ina test tube. Then 3 ppm by volume of a demulsifier was added to thecrude oil and wash water mixture and mixed at 13,000 rpm in a blenderfor 4 seconds. For the sedimentation step, the mixture was allowed tosettle at a temperature of about 120° C. and at an electrical fieldstrength of 10 kV. The volume of free water (mL) was measured at 2, 4,8, 16, and 32 minutes.

The mean water drop is the average measured volume of free water. Themean water drop test indicates both the speed of water drop and theamount of water that had separated from the emulsion. The water dropwith respect to time for Canadian crude oil is shown in FIG. 10 . Themean water drop for the various demulsifier formulations are shown inFIG. 11 .

Venezuelan Heavy Crude Oil

A desalter process with an electric field and desalter mix valve wassimulated to evaluate the synergistic effect a dispersant, in this casea polyisobutenyl succinic anhydride based ester (“PiB ester”), had onbreaking water and crude oil emulsions. For this test, diluted crude oilsimilar to Venezuelan heavy crude oil was prepared. The BS&W of thecrude was about 84 pounds of solids per thousand barrels and 0.1 wt %water. Comp 3.1 was used as the comparative example. For these examples,95 vol % crude oil was mixed with 5 vol % wash water (pH=7) in a testtube. Then 3 ppm of a demulsifier (Comp 3.1) and/or 100 ppm of adispersant (PiBS ester) was added to the crude oil and wash watermixture and mixed at 13,000 rpm in a blender for 4 seconds.

For the sedimentation step, the mixture was allowed to settle at atemperature of about 120° C. and at an electrical field strength of 10kV. The volume of free water (mL) was measured at 2, 4, 8, 16, and 32minutes.

The mean water drop is the average measured volume of free water. Themean water drop test indicates both the speed of water drop and theamount of water that had separated from the emulsion. The water dropwith respect to time for the Venezuelan heave crude oil is shown in FIG.12 . The mean water drop results for the various demulsifier and/ordispersant treatments are shown in FIG. 13 .

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. For example, those skilled inthe art will recognize that the demulsification compositions havemultiple applications, including but not limited to, oil-field or“down-hole” applications or in crude oil refining applications. Suchother examples are intended to be within the scope of the claims if theyhave structural elements that do not differ from the literal language ofthe claims, or if they include equivalent structural elements withinsubstantial differences from the literal languages of the claims.

What is claimed is:
 1. A demulsifying composition for treating ahydrocarbon stream comprising a crude oil, the demulsifying compositioncomprising at least one C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate, an oil phase, an aqueous phase, and a dispersant, whereinsaid demulsifying composition is colloidal, wherein said oil and aqueousphases form a colloidal micellar solution, wherein said demulsifyingcomposition comprises 0.1 wt % to about 90 wt % water based on a totalweight of said demulsifying composition, and wherein said dispersant hasthe following formula:

wherein R is a polyisobutenyl moiety and wherein the dispersant has aweight average molecular weight, Mw, from about 20,000 to about 25,000.2. The demulsifying composition of claim 1, wherein the C₄-C₁₂ alkylphenol-formaldehyde resin alkoxylate has a polymerization number of 2-20and a degree of alkoxylation greater than about 30% and less than about90% relative to the weight of the resin.
 3. The demulsifying compositionof claim 1, wherein said C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate comprises at least two alkyl phenol-formaldehyde resinalkoxylates having different amounts of alkoxylation, and wherein thetwo alkyl phenol-formaldehyde resin alkoxylates comprise a first alkylphenol-formaldehyde resin alkoxylate, having a percent A by weight ofalkoxylation, and a second alkyl phenol-formaldehyde resin alkoxylate,having a percent B by weight of alkoxylation, wherein A minus B is10-50%, and wherein the ratio by weight the first alkylphenol-formaldehyde resin alkoxylate relative to the second alkylphenol-formaldehyde resin alkoxylate is 1:9 to 9:1.
 4. The demulsifyingcomposition of claim 3, wherein the demulsifying composition furthercomprises at least two polyalkylene oxide polyols with a degree ofethoxylation greater than about 30% and less than about 85%, wherein afirst polyalkylene oxide polyol is an ethylene oxide/propylene oxideblock copolymer having the formula:

wherein x, y, and z are any integer greater than one and the moleculehas a weight average molecular weight of 1000-9000; and wherein a secondpolyalkylene oxide polyol is an oxide block copolymer with a weightaverage molecular weight of 3000-25000 and 2-6 branches, each branchcomprising at least one polyalkoxylate block.
 5. The demulsifyingcomposition of claim 1, wherein the demulsifying composition furthercomprises at least one polyalkylene oxide polyol with a degree ofethoxylation greater than about 30% and less than about 85% and a weightaverage molecular weight ranging from about 1000 to about 25,000, andwherein a weight ratio of said C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate to said polyalkylene oxide polyol ranges from about 1:9 toabout 9:1.
 6. The demulsifying composition of claim 5, wherein the atleast one polyalkylene oxide polyol comprises at least two polyalkyleneoxide polyols, and wherein one of said polyalkylene oxide polyols isselected from the group consisting of ethylene oxide/propylene oxideblock polymers, ethylenediamine alkoxylates, polyethyleniminealkoxylates, glycerol alkoxylates, trimethylpropane alkoxylates, andsorbitol alkoxylates.
 7. The demulsifying composition of claim 6,wherein a first polyalkylene oxide polyol is an ethylene oxide/propyleneoxide block copolymer having the formula:

wherein x, y, and z are any integer greater than one and the moleculehas a weight average molecular weight of 1000-9000; and wherein a secondpolyalkylene oxide polyol is an oxide block copolymer with a weightaverage molecular weight of 3000-25000 and 2-6 branches, each branchcomprising at least one polyalkoxylate block.
 8. The demulsifyingcomposition of claim 1, wherein said composition further comprises atleast one member selected from the group consisting of an acid, anon-polar organic solvent, a base, a wetting agent, a corrosioninhibitor, and a water-soluble reverse emulsion breaker.
 9. Thedemulsifying composition of claim 8, wherein the water-soluble reverseemulsion breaker comprises a water soluble cationic polymer.
 10. Thedemulsifying composition of claim 9, wherein the water soluble cationicpolymer comprises a polyamine polymer, a dialkyldiallylammonium polymer,or an acrylamide-based polymer.
 11. The demulsifying compositionaccording to claim 8, wherein said corrosion inhibitor comprises atleast one member selected from the group consisting of amidoethylimidazoline, hydroxyethyl imidazoline, and aminoethyl imidazoline. 12.The demulsifying composition of claim 8, wherein said acid is at leastone selected from the group consisting of acetic acid, citric acid,malic acid, maleic acid, succinic acid, glycolic acid, methane sulfonicacid, dodecylbenzenesulfonic acid, naphthalene sulfonic acid, andp-toluene sulfonic acid; and wherein said non-polar organic solvent isat least one selected from the group consisting of naphtha, lightaromatic naphtha, heavy aromatic naphtha, pentane, cyclopentane, hexane,cyclohexane, benzene, ethyl benzene, 1,2,4-trimethyl benzene,1,3,5-trimethyl benzene, toluene, xylene, cumene, 1,4-dioxane,chloroform, diethyl ether, methyl esters of fatty acids (biodiesel), anddiethylene glycol butyl ether; and wherein said base is at least oneselected from the group consisting of sodium hydroxide and potassiumhydroxide; and wherein the wetting agent is at least one selected fromthe group consisting of sodium dioctyl sulfosuccinic acid and sodiumdodecylbenzene sulfonic acid.
 13. The demulsifying composition of claim1, wherein said C₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylatecomprises at least one member selected from the group consisting of: a)a mixed resin with units of nonylphenol formaldehyde alkoxylate andunits of butylphenol formaldehyde alkoxylate; b) a resin with units ofnonylphenol formaldehyde alkoxylate; and c) a resin with units ofamylphenol formaldehyde alkoxylate.
 14. A demulsifying composition fortreating a hydrocarbon stream comprising a crude oil, the demulsifyingcomposition comprising at least two C₄-C₁₂ alkyl phenol-formaldehyderesin alkoxylates, an oil phase, and an aqueous phase, wherein saiddemulsifying composition is colloidal and said oil and aqueous phasesform a colloidal micellar solution, wherein said demulsifyingcomposition comprises 0.1 wt % to about 90 wt % water based on a totalweight of said demulsifying composition and wherein said at least twoC₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylates have differentamounts of alkoxylation, and wherein the at least two alkylphenol-formaldehyde resin alkoxylates comprise a first alkylphenol-formaldehyde resin alkoxylate, having a percent A by weight ofalkoxylation, and a second alkyl phenol-formaldehyde resin alkoxylate,having a percent B by weight of alkoxylation, wherein A minus B is10-50%, and wherein the ratio by weight of the first alkylphenol-formaldehyde resin alkoxylate relative to the second alkylphenol-formaldehyde resin alkoxylate is 1:9 to 9:1, and wherein at leastone C₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylate is a nonylphenolformaldehyde resin alkoxylate having a polymerization number of about8-9 and 55% ethylene oxide by weight.
 15. The demulsifying compositionof claim 14, wherein each C₄-C₁₂ alkyl phenol-formaldehyde resinalkoxylate has a polymerization number of 2-20 and a degree ofalkoxylation greater than about 30% and less than about 90% relative tothe weight of the resin.
 16. The demulsifying composition of claim 14,wherein the demulsifying composition further comprises at least onepolyalkylene oxide polyol with a degree of ethoxylation greater thanabout 30% and less than about 85% and a weight average molecular weightranging from about 1000 to about 25,000, and wherein a weight ratio ofsaid at least two C₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylates tosaid polyalkylene oxide polyol ranges from about 1:9 to about 9:1. 17.The demulsifying composition of claim 16, wherein the at least onepolyalkylene oxide polyol comprises at least two polyalkylene oxidepolyols, and wherein one of said polyalkylene oxide polyols is selectedfrom the group consisting of ethylene oxide/propylene oxide blockpolymers, ethylenediamine alkoxylates, polyethylenimine alkoxylates,glycerol alkoxylates, trimethylpropane alkoxylates, and sorbitolalkoxylates.
 18. The demulsifying composition of claim 17, wherein afirst polyalkylene oxide polyol is an ethylene oxide/propylene oxideblock copolymer having the formula:

wherein x, y, and z are any integer greater than one and the moleculehas a weight average molecular weight of 1000-9000; and wherein a secondpolyalkylene oxide polyol is an oxide block copolymer with a weightaverage molecular weight of 3000-25000 and 2-6 branches, each branchcomprising at least one polyalkoxylate block.
 19. The demulsifyingcomposition of claim 14, wherein said composition further comprises atleast one member selected from the group consisting of an acid, anon-polar organic solvent, a base, a wetting agent, a corrosioninhibitor, and a water-soluble reverse emulsion breaker.
 20. Thedemulsifying composition of claim 19, wherein the water-soluble reverseemulsion breaker comprises a water soluble cationic polymer.
 21. Thedemulsifying composition of claim 20, wherein the water soluble cationicpolymer comprises a polyamine polymer, a dialkyldiallylammonium polymer,or an acrylamide-based polymer.
 22. The demulsifying compositionaccording to claim 19, wherein said corrosion inhibitor comprises atleast one member selected from the group consisting of amidoethylimidazoline, hydroxyethyl imidazoline, and aminoethyl imidazoline. 23.The demulsifying composition of claim 19, wherein said acid is at leastone selected from the group consisting of acetic acid, citric acid,malic acid, maleic acid, succinic acid, glycolic acid, methane sulfonicacid, dodecylbenzenesulfonic acid, naphthalene sulfonic acid, andp-toluene sulfonic acid; and wherein said non-polar organic solvent isat least one selected from the group consisting of naphtha, lightaromatic naphtha, heavy aromatic naphtha, pentane, cyclopentane, hexane,cyclohexane, benzene, ethyl benzene, 1,2,4-trimethyl benzene,1,3,5-trimethyl benzene, toluene, xylene, cumene, 1,4-dioxane,chloroform, diethyl ether, methyl esters of fatty acids (biodiesel), anddiethylene glycol butyl ether; and wherein said base is at least oneselected from the group consisting of sodium hydroxide and potassiumhydroxide; and wherein the wetting agent is at least one selected fromthe group consisting of sodium dioctyl sulfosuccinic acid and sodiumdodecylbenzene sulfonic acid.
 24. The demulsifying composition of claim14, wherein each C₄-C₁₂ alkyl phenol-formaldehyde resin alkoxylatecomprises at least one member selected from the group consisting of: a)a mixed resin with units of nonylphenol formaldehyde alkoxylate andunits of butylphenol formaldehyde alkoxylate; b) a resin with units ofnonylphenol formaldehyde alkoxylate; and c) a resin with units ofamylphenol formaldehyde alkoxylate.